Nu-(thiazyl-thio-methylene) urethanes



Patented May 14, 1946 V 1 UNITED sTATEs PATENT F 2,400,459 FIC N (THIAZYL-THIO-METHYLENE) V URETHANES Winfield Scott, deceased, late of Akron, Ohio, by Ruth P. Scott, executrix, Akron, Ohio, assignor I r to Wingfoot Corporation, Akron, Ohio, a corporation of Delaware No Drawing. Application August 13, 1943, 4 Serial No. 498,592 7 GClaims. (c1. ace-306.6)

This invention relates to N -(thiaZy1-thiomethylene) urethanes and the process for making the same.

Many materials are known which function as accelerators of the vulcanization of rubber. Different accelerators produce different rates of vulcanization and the choice of accelerator also determines to a large degree the physical characteristics and quality of the vulcanized rubber.

According to the present invention, a new type of accelerator has been discovered which produces an eflicient vulcanization and gives a vulcanized rubber product having excellent properties. The accelerators of the invention are obtained by the interaction of a 2-mercaptothiazole, formaldehyde and a urethane.

The preparation of these accelerators is trated by the following examples:

Example 1 Equimolecular proportions of N-methylol urethane and 2-mercaptobenzothiazole were heated over a gas burner, water being split out. The resulting product was dissolved in chloroform and precipitated by the addition of ether. The white product (which turned light yellow in the air) melted at 127-431 0. Several recrystallizations from alcohol gave a meltin point of 149-150 C. The yield of crude product was quantitative.

Example 2 illus- II II 1 ozm-o-o-Nm HCHO ozm-o-o-Nn-cmon N f O r N 115- 0 OzHa-O-Pi-NH-QHa-S-i/ In addition to the Z-mercaptobenzothiazole used in the examples, various other Z-mercaptothiazoles may also be used, including 2-mercapto 4 methylthiazole, 2-mercapto-4,5-dimethylthiazole, 2-mercapto-4-ethylthiazole, 2- mercaptoquinoline, 2 mercaptothiazoline, 2- mercapto-6-nitrobenzothiazole, 2 mercapto-6- chlorbenzothiazole, 2 mercapto 4 phehylb'enzothiazole, 2-mercapto-4-methylbenzothia2ole, 2- mercapto-G-ethoxybenzothiazole, 2-mercapto-6- methoxybenzothiazole, 2 mercapto-fi-chlor-t'anitrobenzothiazole, 2 mercapto-fi-hydroxybenzothiazole, 2-mercapto-5-nitrobenzothiazole, 2-

mercapto-5-chlorbenzothiazole, the 2-mercapto-' alpha and beta-naphthothiazoles, and other alkyl, aryl, nitro, hydroxy, halo, alkoxy, etc. derivatives of mercaptothiazoles. The ,Z-mercapto-arylenethiazoles and particularly the 2- mercaptobenzothiazoles constitute preferred classes.

As already indicated, paraformaldehyde and other materials which are the equivalent of formaldehyde may also be employed.

Likewise, other urethanes may also be employed in place of the urethane of the examples. In general, these urethanes may be represented by the structural formula R -X-O-N-H in which R1 is selected from the group consisting of alkyl and aralkyl radicals and hydrogen, X is selected from the groupconsisting of oxygen and sulfur, and R2 is selected from the group consisting of alkyl and aralkyl radicals. Further representative examples are methyl urethane,

propyl I urethane; isopropyl urethane, N-methyl urethane, benzyl urethane, furfuryl urethane, cyclohexyl urethane, N-ethyl butyl urethane, etc.

Thus, the accelerator compounds may be represented by the structural formula in which R is a thiazyl radical, R1 is selected from the group consisting of alkyl and aralkyl radicals and hydrogen, X is selected from the group consisting of oxygen and sulfur and R2 is selected from the group consisting of alkyl and aralkyl radicals.

The acceleratorsof the invention are readily incorporated into rubber and produce excellent cures. For example, N-(benzo-thiazyl-thiomethylene) urethane was compounded in rubber according to the following formula:

Parts by weight Smoked sheet rubber 100.0 Zinc oxide 5.0 Sulfur 3.0 Diphenylguanidine 0.1

Accelerator A very good cure was obtained in 60 minutes at 240 F. The ultimate tensile strength was 190 kg./sq. cm. The ultimate elongation was 755%,

and the modulus at 500% elongation was 34.

kg./sq. cm.

What is claimed is:

1. As a new composition of matter, a compound having the structural formula RSOHz-NCX-R:

t. it

in which R is a thiazyl radical, R1 is selected from the group consisting of alkyl and aralkyl radicals and hydrogen, X is selected from the group consisting of oxygen and sulfur and R2 is selected from the group consisting of alkyl and aralkyl radicals.

2. As a new composition of matter, an N- (thiazyl-thio-methylene) urethane having the structural formula in which R is an arylenethiazyl radical, R1 is selected from the group consisting of alkyl and aralkyl radicals and hydrogen, X is oxygen and R2 is selected from the group consisting of alkyl and aralkyl radicals.

4. As a new composition of matter, an N-(aryl- .enethiazyl-thio-methy1ene) thiourethane having the structural formula in which R is'anarylenethiazyl radical, R1 is selected from the group consisting of alkyl and aralkyl radicals'and hydrogen, X is sulfur and R2 is selected from the group consisting of alkyl and aralkyl radicals.

5. As a new composition of matter, an N- (benz'othiazyl-thio-methylene) urethane having the structural formula Rs0H-N-om 1'. i in which R is a benzothiazyl radical, R1 is selected from the group consisting of alkyl and aralkyl radicals and hydrogen, X is oxygen and R2 is selected from the group consisting of alkyl and aralkyl radicals.

6. As a new composition of matter, an N-(benzothiazyl-thio-methylene) thiourethane having the structural formula R-sCH2.N-oRi in which R is a benzothiazyl radical, R1 is selected from the group consisting of alkyl and aralkyl radicals and hydrogen, X is sulfur and R2 is selected from the group consisting of alkyl and aralkyl radicals.

RUTH P. SCOTT,

Emecutrz'a: of the Last Will and Testament of Winfield Scott, Deceased. 

